1. Field of the Invention
The present invention relates to the fabrication of dental prosthodontics, and more particularly to a teaching tool for teaching students the molding process involved in the fabrication of removable dental prosthodontics, such as dentures and the like.
2. Description of the Related Art
Dentures are prosthetic devices constructed to replace missing teeth; they are supported by the surrounding soft and hard tissues of the oral cavity. Modern dentures are most often fabricated in a commercial dental laboratory or by a denturist using a combination of tissue shaded powders polymethylmethacrylate acrylic (PMMA). The process of fabricating a denture typically begins with an initial dental impression of the maxillary and mandibular ridges. Standard impression materials are used during the process. The initial impression is used to create a simple stone model that represents the maxillary and mandibular arches of the patient's mouth.
Once the initial impression is taken, the stone model is used to create a custom impression tray, which is used to take a second and much more detailed and accurate impression of the patient's maxillary and mandibular ridges. A wax rim supported by an acrylic base is fabricated to assist the dentist or denturist in establishing the vertical dimension of occlusion. After this, the jaw relation record is established to marry the position of one arch to the other.
Once the relative position of each arch to the other is known, the wax rim can be used as a base to place the selected denture teeth in correct position. This arrangement of teeth is tested in the mouth so that adjustments can be made to the occlusion. After the occlusion has been verified by the dentist or denturist and the patient, and all phonetic requirements are met, the denture is processed. Processing a denture is typically performed using a lost-wax technique in which the form of the final denture, including the acrylic denture teeth, is invested in stone. This investment is then heated, and when it melts the wax is removed. The remaining cavity is then either filled by forced injection or pouring in the uncured denture acrylic, which is either a heat cured or cold-cured type. After a curing period, the stone investment is removed, the acrylic is polished, and the denture is complete.
When the dentist establishes the vertical dimension of occlusion, and when the jaw relation is established, the dentist is required to manually manipulate materials, primarily operating through touch and sight. It is this part of the process which requires practice to ensure that a proper prosthodontic piece is fabricated. Students do not often have the opportunity to practice this process other than on actual patients. Thus, a denture construction teaching tool solving the aforementioned problems is desired.